Method for detecting dynamic stock level in stock bin limit position based on machine vision

Abstract

The invention relates to a method for detecting the dynamic stock level in a stock bin limit position in an image processing manner based on a digital camera and an auxiliary lighting device. By shooting images of a stock bin and processing the images in real time, the real time monitoring of the dynamic stock level is completed, and an ultralimit alarm for the stock level is realized. By analyzing the characteristics of the stock bin limit position images and adopting the characteristics of particular images extracted in the image processing manner as a basis, the dynamic stock level near the stock bin limit position corresponds to three working states including a detection state, a monitoring state and an alarm state, the ultralimit alarm for the stock level is realized, and the method has the characteristics of good real time performance and high reliability. The method is especially applicable to occasions having safety enforcement requirements for the stock level in the stock bin limit position, such as underground coal bins in coal mines.

Description

technical field [0001] The invention relates to the detection of the material level at the limit position of a silo. The invention specifically relates to the non-contact dynamic detection of the material level at the limit position of the silo by using a digital camera to take images and perform image processing. Background technique [0002] Silo material level detection is an important measure for safe production. Over the years people have adopted various methods to detect the material level of the silo. Commonly used detection methods are: hammer type, electrode type, capacitive type, machine rod type, weighing type, rotary wing wheel type, radar type, ultrasonic type, laser type, nuclear type, etc. Among them, the hammer type, electrode type, capacitive type, machine rod type, weighing type and rotary wing wheel type are contact measurement methods, and the rest are non-contact measurement methods. The methods that can measure the limit position are: hammer type, el...

AI Technical Summary

Problems solved by technology

[0004] (1) The silo has high dust concentration, high humidity, low illumination, poor image quality, and it is difficult for the camera to achieve automatic focus

[0005] (2) The illuminance fluctuates frequently in the silo, for example, there are many large-scale equipment in the coal mine, and the power grid is greatly disturbed, resulting in illuminance fluctuations

[0007] Therefore, due to the special image environment, it is difficult to use ordinary image processing methods for depth measurement to meet the real-time and reliability requirements of silo level measurement, and it is also difficult to achieve long-term and stable detection.

[0008] The patent publication number is CN101270981, which is a material level measurement method and device based on machine vision. It proposes a material level detection method for coal mine underground silos. However, the reliability of this method is difficult to guarantee, and it can only be used as a static continuous measurement. It cannot be used as a dynamic measurement of the limit position, and its practical application is limited

[0011] (1) It is difficult for digital cameras to automatically focus and take reliable images;

[0012] (2) The reliability and precision of the method for measuring material level based on such images are low;

[0013] (3) Can not solve the dynamic measurement problem of limit position;

[0014] (4) Since the silo is a closed and semi-closed environment, it is difficult to monitor and verify the operation of the equipment. There is no self-checking mechanism based on the reliability of the detection system, and the reliability of the system cannot be guaranteed, which is difficult for practical application

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